This invention relates to wave dampening devices for waterbed mattresses and more particularly to fibrous wave dampening batts for dampening the propagation of waves along the upper surfaces of such mattresses.
At present waterbed mattresses are available with a wave dampening layer of fibrous material disposed along the upper surface of the mattress inside the mattress shell. This layer is typically made of short, non-woven polyester fibers bonded together by a resin. This resin is able to penetrate the fibrous batt only to a depth of one inch or so from each side, so that layers formed in this manner are limited to a thickness of approximately two inches. If a thicker batt is desired, it is necessary to mechanically join two or more of the thinner, two-inch layers together by riveting, sewing or the like. Each of these multiple layers must be cut to the proper size after the resin is added.
In addition, polyester does not float in water, so it is necessary to attach buoyant material to the polyester batt in some manner to cause the batt to be positioned properly at the top of the mattress. This, of course, also increases the cost of the wave dampening batt.
At present, waterbed mattresses are shipped to the customer with the wave dampening batt in place inside the mattress. To reduce the bulk of the mattress, the interior of the mattress is put under vacuum. This compresses the fibrous wave dampening batt substantially. Upon removal of the vacuum and inflation of the mattress with water, the fibrous batt recovers only a portion of its pre-compression thickness. This is undesirable since the wave-dampening properties of the batt are directly related to the thickness of the batt.